Tension device for warp yarns in velvet fabric looms



March 17, 1970 GQLOBART 3,500,874

TENSION DEVICE FOR WARP YARNS IN VELVET FABRIG LOOMS Filed July 18, 1968 3 Sheets-Sheet 1 27' 26' 24' 2 19' A 3 22' is 4 IN l/E'NTO/P kAn/v Bamaaae Genoa/M7- March 17, 1970 R. a. GOLOBART 3,500,874

TENSION DEVICE FOR WARP YARNS IN VELVET FABRIC LOOMS Filed July 18, 1968 3 Sheets-Sheet 2 RA M/v 184M605? 60.408419? March 17, 1970 R. a. GOLOBART 3,500,874

TENSION DEVICE FOR WARP YARNS IN VELVET FABRIC LOOMS Filed July 18, 1968 3 Sheets-Sheet 5 INVENTOR RAMN 8AM sum Gama/m7 United States Patent Int. Cl. D03d49/06, 39/16 US. Cl. 139-102 7 Claims ABSTRACT OF THE DISCLOSURE A tension device for the pile warps of a velvet fabric loom comprises an adjustable compression spring arrangement for the guide bars.

The present invention relates to improved tension or takeup devices for the pile warp yarns in velvet fabric looms, of the type which include springs applied to the guide bars of the pile warp yarns.

The known tension devices for the pile warp yarns for velvet fabric looms comprise tension adjuster springs applied directly at one of its extremities to the guide bars of said pile warp yarns and at the other extremity to a suitable fixed point of the loom. These tension systems, whether they operate under traction or compression, exert a minimum tension when the shed is closed, i.e., when the heddles or shafts are in flat position, and as the shed is opened and the shafts are moved, the springs are compressed, thus exerting maximum stress precisely when the shafts are completely raised, with a resulting overload on the elements which actuate said shafts, whether it be a shaft dobby or a suitable cam device.

Thus, these springs effect the maximum stress when, on the contrary, they should exert the minimum stress, i.e., when the shed is open for the insertion of the weft yarn, and they should have the maximum tension when the shed is closed and the loom sley is advanced to push the inserted weft to the line of formation of the fabric. On the other hand, the tension of the springs must be replaced when the article or material is changed in the loom.

The object of the present invention is to solve all of these disadvantages, by accomplishing the objective of fulfilling the functions required by pile warp yarns in velvet looms and effecting the compression work while compensating the tension as the guide bars of the pile yarns are moved forward upon the opening of the shed.

With the present device, it is not necessary to change the tension elements when the article to be manufactured is changed, since it is possible to regulate the tension by a simple adjustment.

The device which is the object of the present invention is composed of a frame formed of two parallel vertical plates separated and braced by tie rods so as to house between them a fixed shaft on which are rotatably mounted the two bell crank levers at a substantially right angle, the upper arms being each coupled by a rod or link to an extremity of the guide bar of the pile yarn, and said lower arms being each joined to a tube inside which slides a shank, which goes through a hinge joint next to its extremity. Around the tube is applied a helicoidal counterspring located between the hinge joint and the lower extremity of the shank; a screw-nut and lock-nut are threaded at the upper extremity of the shank to regulate the tension of the helicoidal counterspring.

For better understanding of the invention, a preferred form embodiment of the invention is described herein- 3,500,874 Patented Mar. 17, 1970 after with reference to the attached drawings, as a non-limiting example.

FIGS. 1, 3 and 4 are side diagrammatic views of the device with cut-out portions for better view, in three different positions of its operation.

FIG. 2 is a diagrammatic plan view of the device with cutaway portions, corresponding to the position of FIG. 1.

FIG. 5 is a side diagrammatic view of the application of the device in a loom for the manufacture of pile fabrics.

In these figures, 1 and 2 are the plates of a frame indicated generally by numeral 3 braced by tie-rods 4 and 5 and the part 6 located in the back portion. In the front portion of plates 1 and 2 is housed a fixed shaft 7 on which rotate the levers 8 and 9 (FIG. 2) having two arms, one upper arm 10 and another lower arm 11; in FIGS. 1, 3 and 4, only the arms corresponding to lever B can be seen.

Since the mechanisms relative to levers 8 and 9 are identical, only those corresponding to lever 8 will be explained, and in FIG. 2, the mechanisms corresponding to lever 9 are designated with the same reference numerals with prime marking.

The lower arm 11 of said lever 8, FIGS. 1, 3 and 4, is hinged at point 12 to journal 13 integral with tube 14 having diametrally opposite slides 15 and 16. Through the inside of said tube 14 slides a rod or shank 17 crossed at its lower extremity 18 by a pin 19, the extremities 20 and 21 of said pin projecting from said tube 14 and pass ing' through the slides 15 and 16 and used to support a washer or ring 22, which in turn supports the extemity 23 of a helicoidal counterspring 24 which envelops tube 14. The other extremity 25 of said spring rests on another washer 26 in contact with a cylindrical part 27 housed partly in a spherical cavity, in part 6 said two parts 27 and 6 being penetrated in slidable relationship crossed by tube 14, from which projects the threaded extremity 28 of rod 17, to which are threaded and act as stop a screw-nut 29 and lock-nut 30 to adjust the pressure of the helicoidal counterspring 24 in accordance with the position of rod 17 with respect to tube 14.

The upper arm 10 of the lever 8 has several holes 31 for the engagement of a rod 32 for the corresponding position adjustment.

The operation is as follows:

In the application of the device to a loom for the manufacture of velvet fabrics, FIG. 5, the positions of the levers 8 and 9 are adjusted in the initial position (FIG. 3) on a support 35 of the loom framing 36, i.e., in the closed shed position, placing the upper arms 10 and 10' of said levers 8 and 9 against the tie rod 4 which acts as stop, adjusting at the same time, by means of screw nuts 29 and 29' and lock nuts 30 and 30 threaded on the threaded extremities 28 and 28 of rods 17 and 17', the position of the helicoidal countersprings 24 and 24.

Upon opening of the shed, the levers 8 and 9 connected by means of links 32 and 32 to guide bars 33 and 33 of the pile yarns 34 and 34', effect a short turn in the direction of arrow F (FIGS. 1 and 3), the upper arms 10 and 10 and lower arms 11 and 11' describing a small arc until journals 13 and 13' encounter the rod 5 (FIG. 4), thus a backward movement of tubes 14 and 14 is effected, which pulls rods 17 and 17' with their screw-nuts 29 and 29 and lock nuts 30 and 30' which act as stop, and said rods 17 and 17 during this movement, effect at the same time a small counterclockwise rotation about the axis of the cylindrical parts 27 and 27 housed partly in part 6 with the semi-spherical cavity, thus obtaining through the upward movement of pins 19 and 19' a compression of the helicoidal countersprings 24 and 24, maintaining a constant tension in the pile warp yarns 34 and 34 in the open shed position and during the change of same.

anexed claims.

I claim:

1. In tension devices for the guide bars of the warp arns in velvet fabric looms comprising a pair of spaced ipports, a transverse vertically spaced tie rod extending etween said supports and parallel with the shed of a mm, a second transverse element extending between said ipports and horizontally spaced rearwardly from the tie )d, a bell crank lever, means to mount said lever for ivotal movement about an axis parallel to the tie rod, a ibular element having one end pivotally connected with n arm of the bell crank lever, the other end of the tubul1 element being loosely slidably received through an pening provided in said second transverse element, a rod lidably received in said tube, a helicoidal spring surounding the tube having one end abutting the second 'ansverse element, means for connecting the inner end t the rod with the other end of the spring, and adjustble stop means for adjusting the position of the rod with aspect to the spring tension.

2. Apparatus defined in claim 1, wherein said second 'ansverse element is provided with a spherical cavity lrrounding the opening for the tubular element, and a all-shaped bearing element is seated in said cavity for butting engagement with the spring.

3. Apparatus defined in claim 1, wherein said one end f the tubular element is formed with an integral journal lember.

4. Apparatus defined in claim 1, wherein said tubular lement is provided with longitudinal slides and the inner lid of the rod is provided with a transverse pin project- 4 ing through the slides for engagement with the other end of the spring.

5. Apparatus defined in claim 4, wherein a pair of washers are disposed one at each end of the spring respectively.

6. Apparatus defined in claim 1, wherein said rod projects outwardly from the rear end of the tube, and a pair of locking nuts are threadedly received thereon for adjusting the stop means.

7. Apparatus defined in claim 1, wherein the other arm of the bell crank lever is provided with a plurality of openings spaced radially from the pivotal axis of the lever at varying distances for selective connection with one end of a link connected at the other end with a loom guide bar.

References Cited UNITED STATES PATENTS 268,250 11/1882 Lister et a1. 139102 324,394 8/1885 Mair et al. 139-102X 374,064 11/1887 Handy 139-102 428,902 5/1890 Foster 1391O2 2,022,834 12/1935 Welch r al. 2,924,957 2/ 1960 Schoenster.

FOREIGN PATENTS 679,523 7/1929 I France. 728,998 12/ 1942 Germany.

JAMES KEE CHI, Primary Examiner US. Cl. X.R 13921 

